Scaffold board

ABSTRACT

A scaffold board ( 10 ) of extruded thermoplastic material. The board ( 10 ) includes a substantially rectangular outer profile and a plurality of strengtheners ( 20 ). The substantially rectangular outer profile is defined by a top wall ( 12 ), a bottom wall ( 14 ) and a pair of side walls ( 16, 18 ). The plurality of strengtheners ( 20 ) each extend between an inner surface of the top wall and an inner surface of the bottom wall. Each of the strengtheners have a middle part ( 20   c ), a pair of top parts ( 20   a,    20   b ), and a pair of bottom parts ( 20   d,    20   e ). The middle part ( 20   c ) is oriented normally to the plane of the top wall ( 12 ) and the bottom wall ( 14 ). The pair of top parts ( 20   a,    20   b ) each extend outwardly from a top of the middle part ( 20   c ) to the inner surface of the top wall ( 12 ) in substantially equal and opposite directions respectively. The pair of bottom parts ( 20   d,    20   e ) each extend outwardly from a bottom of the middle part ( 20   c ) to the inner surface of the bottom wall ( 14 ) in substantially equal and opposite angles.

FIELD OF THE INVENTION

The present invention relates to a scaffold board.

BACKGROUND

The use of scaffolding during construction, demolition, renovation,maintenance and other building tasks is well known and wide spread.Scaffolding typically involves the temporary construction of arectilinear framework of vertical standards, horizontal ledgers andhorizontal transoms. The standards, ledgers and transoms are typicallysteel tubes which are interconnected by clamps. Scaffold boards are laidacross the transoms in order to provide elevated working platforms.Scaffold boards are usually manufactured from solid wood or laminatedveneer lumber (LVL).

There are several disadvantages associated with solid wood and LVLscaffold boards, including that: they are relatively expensive; they arerelatively heavy; they are perishable; they are not UV Light resistant;they are flammable; they are not resistant to chemical contamination;they are not resistant to propagation of mould spores and bacteria; andthey are not recyclable.

United States Patent Publication No. US 2013/0192927 (application Ser.No. 13/754,212) discloses an alternative scaffold board manufacturedfrom poly vinyl chloride (PVC). The disclosed board overcomes some ofthe above mentioned disadvantages (e.g. they are non-perishable, UVlight resistant and recyclable). However, they have the significantdisadvantage of high deflection under load. As such they do not meet avariety of international and Australian Standards, particularly thedeflection test for scaffold boards, which (in Australia and NewZealand) requires deflection of less than 10 mm over a 1 m spanresponsive to a working load limit (e.g. 210 kg) applied centrally. As aresult, this product cannot be used in Australia, nor the USA, UK orCanada (which have similar standards) and many other significantbuilding markets.

Another known alternative scaffold board has been manufactured fromfibre reinforced plastic (FRP). It also overcomes several similardisadvantages of wood/LVL boards. However, it is also a relatively heavyproduct, is produced from a highly flammable type of plastic material,is exceptionally difficult to recycle and has exceptionally highdeflection at moderately high temperatures. As a result, this product issuitable for only very specific applications.

A further known alternative scaffold board has been manufactured frompolypropylene. It also does also not pass Australian standards. Theboard is black and becomes significantly more flexible in sunlight. Itis also able to ignite and transfer a flame.

Scaffold boards have also been produced from aluminium, which sufferfrom similar disadvantages in terms of relatively high material andproduction cost and relatively high weight.

OBJECT OF THE INVENTION

It is an object of the present invention to substantially overcome, orat least ameliorate, one or more of the above disadvantages.

SUMMARY OF THE INVENTION

Accordingly, in a first aspect, the present invention provides ascaffold board of extruded thermoplastic material, the board including:

a substantially rectangular outer profile defined by a top wall, abottom wall and a pair of side walls; and

a plurality of strengtheners, each extending between an inner surface ofthe top wall and an inner surface of the bottom wall,

wherein each of the strengtheners have:

-   -   a middle part oriented normally to the plane of the top wall and        the bottom wall;    -   a pair of top parts, each extending outwardly from a top of the        middle part to the inner surface of the top wall in        substantially equal and opposite directions respectively; and    -   a pair of bottom parts, each extending outwardly from a bottom        of the middle part to the inner surface of the bottom wall in        substantially equal and opposite angles.

The top wall, the bottom wall, the side walls and the strengthenerspreferably extend longitudinally along a length of the scaffold board.

The top wall, the bottom wall, the side walls and the strengtheners arepreferably integrally formed.

The pair of top parts of each strengthener preferably defines atriangular longitudinal recess with the adjacent inner surface of thetop wall. The pair of bottom parts of each strengthener preferablydefines a triangular longitudinal recess with the adjacent inner surfaceof the bottom wall.

In one form, a hexagonal longitudinal recess is preferably definedbetween adjacent said strengtheners. In another form, an octagonallongitudinal recess is preferably defined between adjacent saidstrengtheners.

The top wall, the bottom wall and the side walls are preferably thickerthan the middle parts, the top parts and the bottom parts.

The top wall and the bottom wall preferably include textured non-slipouter surfaces

The board is preferably extruded from PCV, most preferably type k62 ork66.

In a second aspect, the present invention provides a scaffold board ofextruded thermoplastic material, the board including:

a substantially rectangular outer profile defined by a top wall, abottom wall and a pair of side walls;

a plurality of top triangular hollow recesses extending longitudinallythrough the board, each having one side parallel to the plane of the topwall;

a plurality of bottom hollow triangular recesses extendinglongitudinally through the board, each having one side parallel to theplane of the bottom wall; and

a plurality of hollow hexagonal or octagonal recesses extendinglongitudinally through the board, each being positioned between adjacentopposed pairs of top triangular recesses and bottom triangular recesses.

In one form, the plurality of hollow recesses extending longitudinallythrough the board between adjacent opposed pairs of top triangularrecesses and bottom triangular recesses are hexagonal. In another form,the plurality of hollow recesses extending longitudinally through theboard between adjacent opposed pairs of top triangular recesses andbottom triangular recesses are octagonal.

The top wall, the bottom wall, the side walls are preferably integrallyformed with the top triangular recesses, the bottom triangular recessesand the hexagonal/octagonal recesses.

The top wall and the bottom wall preferably include textured or non-slipouter surfaces

The board is preferably extruded from PCV, most preferably type k62 ork66.

In a third aspect, the present invention provides a scaffold board ofextruded thermoplastic material, the board including:

a substantially rectangular outer profile defined by a top wall, abottom wall and a pair of side walls; and

an internal honeycomb strengthening structure, within the top wall, thebottom wall and the pair of side walls, defined by a row oflongitudinally extending cells, each of the cells defined by a 6 or 8sided polygon with its longest dimension oriented normally to the planeof the top wall and the bottom wall.

In one form, the polygon is a hexagon. In another form, the polygon isan octagon.

The top wall, the bottom wall, the side walls and the strengthenerspreferably extend longitudinally along a length of the scaffold board.

The top wall, the bottom wall, the side walls and the honeycombstrengthening structure are preferably integrally formed.

The top wall, the bottom wall and the side walls are preferably thickerthan the walls of the honeycomb strengthening structure.

The top wall and the bottom wall preferably include textured non-slipouter surfaces

The board is preferably extruded from PCV, most preferably type k62 ork66.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way ofexamples only, with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of an embodiment of scaffold board;

FIG. 2 is an enlarged cross sectional end view of the scaffold boardshown in FIG. 1;

FIG. 3 is an enlarged partial detail view of the scaffold board shown inFIG. 2;

FIG. 4 is an enlarged cross sectional end view of a second embodiment ofscaffold board.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 3 show a first embodiment of a scaffold board 10 produced byextrusion from poly vinyl chloride (PVC) thermo plastic material. Asexamples, PVC type k62 or k66 is used, with the following formula perHundred Parts PVC resin:

Ingredients PHR Range PVC 100 Calcium Carbonate  0.0-25.0 Talc  0.0-40.0Impact Modifier  2.0-15.0 Organic Based Stabilizer 4.5-7.5 Lubricant0.4-1.2 Processing Aid 0.1-1.2 Flame Retardants  0.1-15.0 Wax 0.1-1.2 UVStabilizer 0.1-0.8 Titanium Di Oxide 1.0-7.0 Colouring Pigments Dependson Requirements

As will be understood by persons skilled in the art, the abovecomponents can be increased or reduced to tailor the formula to suitparticular applications, climates and temperature ranges.

The board 10 is produced in dimensions matching those of existing woodboards in order to suit existing scaffolding equipment. The board 10 is230 mm wide, 39 mm thick (including the hot rolled grip discussed below)and produced in 2400 mm and 3600 mm lengths.

As best shown in FIG. 2, the board has a substantially rectangular outerprofile defined by a top wall 12, a bottom wall 14 and pair of side wall16 and 18. The walls 12, 14, 16 and 18 are all approximately 4 mm thick.The interior of the board 10 is substantially hollow aside from aplurality of strengtheners, indicated generally by the reference numeral20, which each extend between an inner surface of the top wall 12 and aninner surface of the bottom wall 14.

The strengtheners 20 each have a pair of top parts 20 a and 20 b, amiddle part 20 c and a pair of bottom parts 20 d and 20 e, which are allabout 3 mm thick. The top parts 20 a and 20 b each extend the outwardlyfrom the top of the middle part 20 c to the inner surface of the topwall 12 in substantially equal and opposite directions respectively. Thebottom parts 20 d and 20 e each extend outwardly from the bottom of themiddle part 20 c to the inner surface of the bottom wall 14 insubstantially equal and opposite directions respectively. The pairs oftop parts 20 a and 20 b each define a triangular longitudinal recess 22with the adjacent inner surface of the top wall 12. Similarly, the pairsof bottom parts 20 d and 20 e each define a triangular longitudinalrecess 24 with the adjacent inner surface of the bottom wall 14.Hexagonal longitudinal recesses 26 are defined between adjacentstrengtheners.

As the board 10 is extruded, the top wall 12, the bottom 14, the sidewalls 16 and 18 and the strengtheners 20 all extend longitudinally alongthe entire length of the board 10. The top wall 12, the bottom wall 14,the side walls 16 and 18, and the strengtheners 20 are also integrallyformed.

As best shown in FIG. 3, the outer surfaces of the top and bottom walls12 and 14 include a number of longitudinal (anti-slip) ridges 28 formedthereon, to enhance grip. The ridges 28 are formed using through the useof a textured hot roller.

Another way to describe the internal strengtheners 20 is that theytogether form an internal honeycomb strengthening structure defined by arow of longitudinally extending cells 30. Each of the cells 30 isdefined by a hexagon with its longest dimension orientated normally tothe plane of the top and bottom walls 12 and 14.

FIG. 4 shows a second embodiment of scaffold board 10′. The board 10′ issimilar to that previously described and like reference numerals aresued to denote like features. However, in the board 10′, thestrengtheners 20 are slightly more widely spaced, resulting in octagonalrecesses 26′ therebetween.

The construction of the boards 10/10′, particularly the strengthenersand honeycomb cells, provides them with superior flexural rigidity andthe ability to meet the Australian Standards deflection test previouslymentioned. The boards 10/10′ are also lighter than the known boardspreviously discussed with the 2400 mm and 3600 mm length boards weighing10.8 kg and 16.2 kg respectively. This weight reduction provides severaladvantages. Firstly, it reduces the material required to produce theboard, which saves production and manufacturing cost. Transport andmanual handling costs are also reduced. Secondly, the board 10 is lightenough to be able to be passed by hand between levels during erection ordismantling of a scaffold structure, as opposed to being carried betweenscaffold levels up stairs and/or ladders, which greatly reduces the timeof both of those tasks.

The boards 10/10′ also maintains the other advantages associated withthermo plastic construction over wooden/LVL boards including being:non-perishable; highly resistant to UV; self-extinguishing for flame;highly impact resistant; highly corrosion resistant; not allowing fortransfer of radioactive particles; not contaminable by range ofchemicals including asbestos; not allowing propagation of mould sporesand bacteria; not allowing for infestation by insects; recyclable andenvironmental sustainable; and being colourable so as to be easilydistinguishable for different uses.

Although the invention has been described with reference to preferredembodiments, it will be appreciated that the invention can be embodiedin many other forms.

1. A scaffold board of extruded thermoplastic material, the boardincluding: a substantially rectangular outer profile defined by a topwall, a bottom wall and a pair of side walls; and a plurality ofstrengtheners, each extending between an inner surface of the top walland an inner surface of the bottom wall, wherein each of thestrengtheners have: a middle part oriented normally to the plane of thetop wall and the bottom wall; a pair of top parts, each extendingoutwardly from a top of the middle part to the inner surface of the topwall in substantially equal and opposite directions respectively; and apair of bottom parts, each extending outwardly from a bottom of themiddle part to the inner surface of the bottom wall in substantiallyequal and opposite angles.
 2. The scaffold board as claimed in claim 1,wherein the top wall, the bottom wall, the side walls and thestrengtheners extend longitudinally along a length of the scaffoldboard.
 3. The scaffold board as claimed in claim 1, wherein the topwall, the bottom wall, the side walls and the strengtheners areintegrally formed.
 4. The scaffold board as claimed in claim 1, whereinthe pair of top parts of each strengthener defines a triangularlongitudinal recess with the adjacent inner surface of the top wall. 5.The scaffold board as claimed in claim 4, wherein the pair of bottomparts of each strengthener defines a triangular longitudinal recess withthe adjacent inner surface of the bottom wall.
 6. The scaffold board asclaimed in claim 4, wherein a hexagonal longitudinal recess is definedbetween adjacent said strengtheners.
 7. The scaffold board as claimed inclaim 1, wherein an octagonal longitudinal recess is defined betweenadjacent said strengtheners.
 8. The scaffold board as claimed in claim1, wherein the top wall, the bottom wall and the side walls are thickerthan the middle parts, the top parts and the bottom parts.
 9. Thescaffold board as claimed in claim 1, wherein the top wall and thebottom wall include textured non-slip outer surfaces.
 10. The scaffoldboard as claimed in claim 1, wherein the board is extruded from PCV. 11.The scaffold board as claimed in claim 10, wherein the board is extrudedfrom PCV type k62 or k66.
 12. A scaffold board of extruded thermoplasticmaterial, the board including: a substantially rectangular outer profiledefined by a top wall, a bottom wall and a pair of side walls; aplurality of top triangular hollow recesses extending longitudinallythrough the board, each having one side parallel to the plane of the topwall; a plurality of bottom hollow triangular recesses extendinglongitudinally through the board, each having one side parallel to theplane of the bottom wall; and a plurality of hollow hexagonal oroctagonal recesses extending longitudinally through the board, eachbeing positioned between adjacent opposed pairs of top triangularrecesses and bottom triangular recesses.
 13. The scaffold board asclaimed in claim 12, wherein the plurality of hollow recesses extendinglongitudinally through the board between adjacent opposed pairs of toptriangular recesses and bottom triangular recesses are hexagonal. 14.The scaffold board as claimed in claim 12, wherein the plurality ofhollow recesses extending longitudinally through the board betweenadjacent opposed pairs of top triangular recesses and bottom triangularrecesses are octagonal.
 15. The scaffold board as claimed in claim 12,wherein the top wall, the bottom wall, the side walls are integrallyformed with the top triangular recesses, the bottom triangular recessesand the hexagonal/octagonal recesses.
 16. The scaffold board as claimedin claim 12, wherein the top wall and the bottom wall include texturedor non-slip outer surfaces.
 17. The scaffold board as claimed in claim12, wherein the board is extruded from PCV.
 18. The scaffold board asclaimed in claim 17, wherein the board is extruded from PCV type k62 ork66.
 19. A scaffold board of extruded thermoplastic material, the boardincluding: a substantially rectangular outer profile defined by a topwall, a bottom wall and a pair of side walls; and an internal honeycombstrengthening structure, within the top wall, the bottom wall and thepair of side walls, defined by a row of longitudinally extending cells,each of the cells defined by a 6 or 8 sided polygon with its longestdimension oriented normally to the plane of the top wall and the bottomwall.
 20. The scaffold board as claimed in claim 19, wherein the polygonis a hexagon.
 21. The scaffold board as claimed in claim 19, wherein thepolygon is an octagon.
 22. The scaffold board as claimed in claim 19,wherein the top wall, the bottom wall, the side walls and thestrengtheners extend longitudinally along a length of the scaffoldboard.
 23. The scaffold board as claimed in claim 19, wherein the topwall, the bottom wall, the side walls and the honeycomb strengtheningstructure are integrally formed.
 24. The scaffold board as claimed inclaim 19, wherein the top wall, the bottom wall and the side walls arethicker than the walls of the honeycomb strengthening structure.
 25. Thescaffold board as claimed in claim 19, wherein the top wall and thebottom wall include textured non-slip outer surfaces.
 26. The scaffoldboard as claimed in claim 19, wherein the board is extruded from PCV.27. The scaffold board as claimed in claim 26, wherein the board isextruded from PCV type k62 or k66.